The protocol attribute should be removed for system.network.connections metrics

[codeboten]

What are you trying to achieve?

Since UDP has no state, I propose UDP and TCP connection metrics should be split into protocol specific metric for each supported protocol.

If folks agree, I will open a PR to mark system.network.connections as deprecated in favour of:

system.network.tcp.connections
system.network.udp.connections

Additional context.

The work for this was previously done in open-telemetry/opentelemetry-specification#2675 and reverted in open-telemetry/opentelemetry-specification#2748. See open-telemetry/opentelemetry-specification#2726 for additional context

[mx-psi]

@jsuereth Can we transfer this to the semantic-conventions repository?

[dmitryax]

@codeboten, is this still applicable after the revert is done in open-telemetry/opentelemetry-specification#2726? Can we close it now?

[mx-psi]

@codeboten Can you help us with the question above?